Watch ‘Undercover’ Review: A Stern French Thriller of State Corruption

Whenever a film begins with a disclaimer asserting that the story you’re about to see is fictional — and furthermore, that what shall unfold on-screen “should not be considered a reflection of a reality” — it’s hard not to go in assuming the exact opposite. Why protest so much if there’s no factual basis there? In the case of “Undercover,” our skepticism is precisely the filmmakers’ intent: That introductory, legally obligatory text could hardly make its irony any clearer with actual scare quotes. Names have been changed, but anyone familiar with the headlines can tell that Thierry de Peretti’s no-frills, teeth-gritted procedural thriller has been drawn from the real-life case of former French anti-narcotics chief Francois Thierry, charged in 2017 with complicity in large-scale drug smuggling using police resources. It’s a sensational affair that de Peretti treats with sober practicality, emulating the patient investigative techniques of the journalist who emerges — in tandem with his chief informant — as the story’s bone-weary hero.

It’s from real-life mole and whistleblower Hubert Avoine’s book “L’infiltré,” co-written with Libération journo Emmanuel Fansten, that de Peretti and Jeanne Aptekman have built their methodical screenplay — though it’s the two men’s collaboration, rather than Avoine’s earlier, intrepid work in Thierry’s bureau, that proves the focus of the film. That makes the English-language title “Undercover” somewhat ill-fitting, as well as forgettably generic: A variation of the French title, which translates as “Investigation Into a State Scandal,” might have been more evocative and enticing.

That’s something for international distributors to consider as this eminently accessible, sellable item — further buoyed by a cast of familiar French faces, including a slithery Vincent Lindon as the film’s Thierry proxy — travels the festival circuit following its San Sebastian competition premiere. For de Peretti, confidently stepping up to a more expansive project while retaining the unfussy human concerns of his smaller, Corsica-set features “Apaches” and “A Violent Life,” this is a persuasive calling card for larger-scale genre fare, directed with mobility and muscle.

Hubert Avoine is none too subtly disguised here as Hubert Antoine (Roschdy Zem), introduced as a complicit observer to a massive, multi-ton cannabis drop in Marbella in the film’s taut, atmospheric opening sequence. Encroaching motorboats slash the dawn silence, cuing a frenzy of activity, with apparent cops among those fetching and carrying. Is it a bust or a handover? Claire Mathon’s camera is compellingly fluid but keeps a cagey distance from proceedings, mirroring Hubert’s own inside-outside stance. A longtime infiltrator of trafficking rings, he has been enlisted by OCRTIS (France’s anti-narcotics police department) to oversee the Marbella operation — though he gradually senses that he isn’t working for the good guys. Years later, with OCRTIS chief Jacques Billard (Thierry) under scrutiny after customs seize seven tons of cannabis in Paris, Hubert turns to journalist Stéphane Vilner (Pio Marmaï) to tell all, accusing Billard of turning his department into the country’s biggest trafficker.

“I’m neither a cop nor a thug,” he says, and Zem’s mournful, contained performance mines considerable tension from the character’s liminal morality: It emerges that there’s another, time-sensitive reason why he’s so eager to come clean, but is he out to repair the whole system or just his conscience? The journalist’s role in all this may seem more straightforwardly heroic, but Marmaï — his brutish charisma ideally deployed — plays Vilner as equal parts bully and sympathetically driven, earnest crusader. There’s a flinty fragility underpinning the men’s friendship throughout: They’re fighting the same cause, but also using each other to slightly different ends. “You’ll write another book after this, but my combat continues,” Hubert tersely tells the journalist, not entirely unreasonably.

Around this core not-quite-buddy story, a large ensemble of dependable players enacts the human machinery at work in the Libération investigation and protracted legal proceedings. If Alexis Manenti seems underused as one of Vilner’s colleagues, Valeria Bruni-Tedeschi, cast as a public prosecutor, makes her cameo count in a fraught, furious one-scene standoff with Lindon’s toxic official where he tries to explain away gross malpractice as unorthodox progress. “The war on drugs finally moves forward, and you close your eyes,” he fumes. Nobody’s buying it, yet de Peretti’s systematic, detail-oriented, not fully resolved film demonstrates how long it nonetheless takes for corrupt, cornered bodies to course-correct.